Apparatus for measuring loads in ropes

ABSTRACT

Apparatus for measuring the loading of a rope comprising three rope engagement members spaced along a resilient support for engaging opposite sides of the rope, one of said members being carried on a carrier and being displaceable by eccentric pivotation or sliding on the carrier, upon movement of an adjustment member, to deflect the rope, means being provided for measuring distortion of the resilient support in response to the rope deflection.

United States Patent King [451 Apr. 4, 1972 APPARATUS FOR MEASURINGLOADS IN ROPES Inventor: Henry King, Langley, England Assignee: FulmerResearch Institute Limited, Stoke Poges, Buckinghamshire, England Filed:Nov. 4, 1970 Appl. No.: 86,992

Related US. Application Data Continuation of Ser. No. 741,472, July l,1968, abandoned.

Foreign Application Priority Data July 13, 1967 Great Britain..32,398/67 U.S. Ci.. 73/144 Int. Cl. ..G0ll 5/04' Field of Search [56]References Cited UNITED STATES PATENTS 2,183,817 12/1939 Mathey ..73/l442,200,572 5/1940 Bolen ..73/144 2,319,299 5/1943 Converse... .....73/141A 2,471,999 5/1949 Boos ..73/144 2,795,136 6/1957 Matt 73/144 2,986,9326/1961 Melton ..7 3/ l 44 3,310,981 3/1967 Nixon et al. ....,73/l443,398,575 8/1968 Saxl ..73/144 Primary Examiner-Charles A. RuehlAttorney-Stevens, Davis, Miller & Mosher 57 ABSTRACT Apparatus formeasuring the loading of a rope comprising three rope engagement membersspaced along a resilient support for engaging opposite sides of therope, one of said members being carried on a carrier and beingdisplaceable by eccentric pivotation or sliding on the carrier, uponmovement of an adjustment member, to deflect the rope, means beingprovided for measuring distortion of the resilient support in responseto the rope deflection.

16 Claims, 9 Drawing Figures APPARATUS FOR MEASURING LOADS IN ROPES Thisis a continuation of application Ser. No. 741,472, filed July 1, 1968.

The present invention relates to an apparatus for measuring the loadingof a rope, the expression "rope as employed hereinafter being intendedto include cables.

For measuring the loading of a rope, it has previously been proposed toprovide an apparatus having means for engaging the rope at three spacedpositions for deflecting the rope, and means for measuring distortion ofa resilient member, in response to the rope deflection, as measure ofthe loading of the rope.

It is an object of the present invention to provide an apparatus asdescribed above with improved means for deflecting the rope.

The present invention provides an apparatus for measuring the loading ofa rope, comprising three rope engagement members spaced apart along aresilient support for engaging a rope, one of the rope engagementmembers being a rope deflector which is displaceable relative to thesupport for deflecting the rope, and means for measuring distortion ofthe resilient support in response to the rope deflection, wherein therope deflector is carried on a carrier connected to an adjustment memberand is displaceable by eccentric pivotation or sliding of the ropedeflector on the carrier upon movement of the carrier in response torotation of the adjustment member.

The invention will be more readily understood from the followingdescription of an embodiment thereof, given by way of example, withreference to the accompanying drawings, in which:

FIG. 1 shows a side view of an apparatus for measuring the loading in arope, the apparatus being shown in position on the rope;

FIG. 2 shows a view taken in section along the line 2-2 of FIG. 1; and

FIG. 3 shows a side view of a modification of the apparatus ofFIGS. 1and 2;

FIG. 4 shows a view taken in section along the line 4-4 of FIG. 3;

FIG. 5 shows a partial side view of another modification of theapparatus of FIGS. 1 and 2;

FIG. 6 shows a side view of a further modification of the apparatus ofFIGS. 1 and 2;

FIG. 7 shows a still further modification of the apparatus of FIGS. 1and 2;

FIG. 8 shows a view taken in transverse section through apparatus formeasuring the loading of a rope employing a wedging action to deflectthe rope; and

FIG. 9 shows a view taken in section along the line 9-9 of FIG. 8.

As shown in the drawing, a rope 1 extends through apparatus comprising aresilient support in the form of a beam 2 on which two rollers 3 arefreely rotatably mounted on arms 4 at the ends of the beam 2. A roller 5is freely rotatably mounted on a carrier in the form of an axle 6 which,as shown in FIG. 2 is rigid with a cylindrical member 6a from whichextends an adjustment member in the form of a handle 7. Axle 6 has anaxis Al and roller 5 has an axis A2 as shown in FIGS. 1 and 2. Thecylindrical member 6a is rotatable relative to the beam 1, and the axle6 and roller 5 are eccentrically disposed relative to the cylindricalmember 6a, so that by rotating the cylindrical member 6a by means of thehandle 7, the roller 5 can be pressed against the rope I. The roller 5thus serves as a rope deflector for deflecting the rope I.

An arm 8 is releasably secured at one end thereof by screws 9 to one endof the beam 2, and the other end 10 of the arm 8 carries a dial gauge 11for mechanical measurement of bending of the beam 2 as described below.

Four electrical resistance strain gauges 12 are cemented to the frameand are connected in a bridge circuit for electrical measurement of thebending of the beam.

By unscrewing the screws 9, the arm 8 and dial gauge 11 can be removedwhen mechanical measurement by the dial gauge 11 is not required.However, if it is not required to have the arm 8 removable, the beam 2may be made in one piece with the arm 8.

The operation of the above-described apparatus is as follows:

For measuring the loading in the rope I, the apparatus is positionedwith the roller 5 at one side of the rope and the rollers 3 at theopposite side of the rope. The handle 7 is then manually rotated throughinto the position in which it is shown in FIG. 1, which causes theroller 5 to move relative to the rollers 3 and outwardly from the beam2, thereby deflecting the rope 1.

This deflection of the rope 1 imposes a strain on the beam 2proportioned to the loading in the rope 1, and the beam 2 isconsequently distorted by bending. The distortion of the beam 2,measured by the dial gauge 11 or the bridge circuit incorporating thestrain gauges 12, represents the loading in the rope I. v

The electrical resistance strain gauges 12 are wire or foil straingauges for long term stability and maybe temperature compensated.Alternatively, semi-conductor strain gauges may be employed with asimple read-out indicator.

Instead of manual actuation of the rope deflector roller 5 by means ofthe handle 7, the cylindrical member 6a and the handle 7 may be replacedby an electric motor drive as shown in the modified apparatusillustrated in FIGS. 3 and 4. In this modification, the cylindricalmember 6a is replaced by a sprocket wheel 6b driven through an endlesschain 13 from a sprocket wheel 14 secured to a shaft 14a which isrotatable in one end of the beam 2. The shaft 14a is secured to a wormwheel 15, which is driven by an electric motor 16 through a worm 17, themotor 16 being secured to an extension 2a of the beam 2 by screws 18.

The electric motor 16 can be switched on from a remote control point todeflect the rope I, a switch actuator (not shown) being provided on thesprocket wheel 6b for actuating a microswitch (not shown) to de-energizethe electric motor 16 when the roller 5 has deflected the rope I by therequired amount.

The electric motor 16 may be replaced by a handwheel, as shown in FIG.5, in which there is shown a modification of the apparatus of FIGS. 3and 4. In this modification, a worm 18 is secured to a shaft 18ajoumalled in shaft bearings 18b fixed to the beam 2. The worm l8 mesheswith the worm wheel 15 and can be rotated by the handwheel, which isindicated by reference numeral 19 and fixed to the shaft 18a.

A further modification of the apparatus is illustrated in FIG.

6 and has a crank wheel 60 connected by a connecting rod 22 to a pistonrod 23, the deflector roller 5 being eccentrically connected to thecrank wheel 60. Y A piston head 230 on the piston rod 23 is slidable ina cylinder 24 secured to a mounting plate 2b carried by the beam 1, oilsupply and discharge pipes 24a and 24b being connected to the cylinder24 for supplying oil to displace the piston head 230 by an amountsufficient to rotate the crank wheel 6c through slightly less than 180.

In the apparatus shown in FIG. 7, three rollers are again provided forengaging the rope I, but in this case the middle roller, indicated byreference numeral 3a, is rotatable about an axis which is fixed relativeto the beam 1, and a movable deflector roller (not shown) is mounted atthe left hand end of the beam 2, as viewed in FIG. 7, thedeflector-roller being freely rotatable on a carrier axle (not shown)which is carried eccentrically on an axle 27 of a worm wheel 28. Anadjustment member in the form of handwheel 29 connected to a shaft 30which is joumalled in bearings 31 and secured to a worm 32 is providedfor rotating the axle 27 to deflect the rope I.

Instead of employing an eccentrically mounted deflector roller, theapparatus shown in FIGS. 8 and 9 has a deflector roller 33 freelyrotatably mounted on a hub 34 which is slidably supported on a carrierin the form of a shaft 35. More particularly, the hub 34 is slidable ona middle portion 36 of the shaft 35, the shaft portion 36 having arectangular crosssection and being inclined relative to end portions 37and 38 of the shaft 35. The shaft end portion 37 is slidable in a wall40 of a hollow portion of a beam 42 and is keyed to the wall 40 by a key43. The shafi end portion 38 is in threaded engagement with anadjustment member in the form of a handwheel 45 which is rotatablysecured to the beam 42 by a thrust plate 46.

The beam 42 is provided with a further pair of rope engagement rollerssimilar to the rollers 3 of FIG. 1 and with an arm and dial gauge and/orelectrical strain gauges similar to those described above for measuringdistortion of the rope.

In operation of this apparatus, the handwheel 45 is rotated to cause theshaft 35 to move to the left, as viewed in FIG. 8, i.e., in a directioninclined relative to the axis of the shaft middle portion 36. The hub 34is prevented from moving in this direction and is consequently movedperpendicular to this direction by a wedging action between the shaftmiddle portion 36 and the hub 34. In this way, the deflector roller 33is displaced relative to the beam 42 to deflect the rope. Instead of thehandwheel 45, an adjustment member rotatable byan electric motor orhydraulic means may be provided for displacing the shaft 35.

In each of the above-described apparatuses, the rollers can be readilyreplaced by rollers of difi'erent dimensions for adaptation to variousrope thicknesses.

The above described apparatuses are simple to operate and may beemployed e.g., to measure loadings in ropes such as stay wires for radioand yacht masts, endless rope conveyors, catenary wires and signalwires.

The apparatuses are of rigid and readily portable construction and canbe fitted onto the rope while the rope is taut and without having toremove and replace any part of the apparatus.

Since the rollers are freely rotatable, the apparatuses may be used onrunning ropes, in which case any convenient means may be used foranchoring the apparatus. For use with plastics protected wires, therollers may be coated with plastics material to avoid damage to thewires.

1 claim:

1. An apparatus for measuring the loading of an elongate member,comprising a resilient elongate support, first and second engagementmembers spaced apart along said resilient support for engaging one sideof said elongate member, a carrier member pivotable relative to saidresilient support about a first axis substantially midway between saidfirst and second engagement members along said resilient support, athird engagement member mounted on said carrier member and pivotablerelative to said support about a second axis for engaging the oppositeside of said elongate member, said carrier member being pivotable aboutsaid first axis from a first position, in which said deflector is fullyreleased into a second position, in which said deflector is fullydisplaced by the maximum possible distance towards said elongate memberfor deflecting said elongate member, said first and second axes beingaligned with the reaction force exerted by said elongate member on saidthird displacement member when the latter is in said second position,means for effecting said pivotation of said carrier member, and meansfor measuring distortion of said resilient support on movement of saiddisplaceable deflector into said second position, said apparatus beingopen at one side thereof to allow engagement of said engagement memberswith said elongate member by relative laterial movement of saidapparatus and said elongate member.

2. An apparatus as set forth in claim 1, wherein said means foreffecting pivotation comprise a handle fixed to said carrier.

3. An apparatus as set forth in claim 1, further comprising an armsecured by one end thereof to the support and extending along and spacedfrom the support, said distortion measur- 4. An apparatus as set forthin claim 1, wherein said first,

second and third engagement members each comprise a freely rotatableroller, means being provided for releasably securing sard rollers tosaid support, whereby said rollers are readily replaceable by rollers ofdifi'erent dimensions.

5. An apparatus as set forth in claim 1, wherein said pivotation meanscomprises an electric motor.

6. An apparatus as claimed in claim 1, wherein said pivotation meanscomprises a piston and cylinder and a crank.

7. An apparatus as claimed in claim 1, wherein said pivotation meanscomprises a handwheel, and a worm and worm connecting said handwheel tosaid carrier.

8. An apparatus for measuring the loading of an elongate member,comprising a resilient elongate support, three engagement members spacedapart along said resilient support for engaging said elongate member, acarrier mounted on said support, one of said engagement memberscomprising a displaceable deflector member mounted on said carrier, asurface on said carrier engaging said deflector member, means mountingsaid carrier for movement relative to said deflector in a directioninclined to said surface, and means for effecting the movement of saidcarrier in said direction to move said deflector member from a releasedposition and to an engaged position for deflecting said resilientsupport, and means for measuring the deflection of said resilientsupport as an indication of the loading of said elongate member. I

9. An apparatus as set forth in claim 8, wherein said means forefi'ecting movement of said carrier comprise a manually rotable memberin threaded engagement with said carrier.

10. An apparatus as claimed in claim 8, wherein the three ropeengagement members each comprise a freely rotatable roller.

11. An apparatus as claimed inclaim 10, wherein the rollers arereplaceable by rollers of diflerent dimensions for adapting theapparatus to different rope thicknesses.

12. An apparatus as claimed in claim 11, wherein the distortionmeasuring means comprise a mechanical gauge.

13. An apparatus as claimed in claim 12, wherein the mechanical gauge ismounted on an arm extending from the support member.

14. An apparatus as claimed in claim 13, wherein the arm is movablyconnected to the support member.

15. An apparatus as claimed in claim 8, wherein the measuring meanscomprise an electrical strain gauge connected to the resilient support.

16. An apparatus for measuring the loading of an elongate member,comprising a resilient elongate support, first and second engagementmembers spaced apart along said resilient support for engaging one sideof said elongate member, a carrier member pivotable relative to saidresilient support about a first axis substantially midway between saidfirst and second engagement members along said resilient support, athird engagement member mounted on said carrier member and pivotablerelative to said support about a second axis for engaging the oppositeside of said elongate member, said carrier member being pivotable aboutsaid first axis from a first position, in which said deflector is fullyreleased into a second position, in which said deflector is fullydisplaced by the maximum possible distance towards said elongate memberfor deflecting said elongate member, means for effecting said pivotationof said carrier member, and means for measuring distortion of saidresilient support on movement of said displaceable deflector into saidsecond position, said apparatus being open at one side thereof to allowengagement of said engagement members with said elongate members byrelative lateral movement of said apparatus and said elongate member.

i i i i

1. An apparatus for measuring the loading of an elongate member,comprising a resilient elongate support, first and second engagementmembers spaced apart along said resilient support for engaging one sideof said elongate member, a carrier member pivotable relative to saidresilient support about a first axis substantially midway between saidfirst and second engagement members along said resilient support, athird engagement member mounted on said carrier member and pivotablerelative to said support about a second axis for engaging the oppositeside of said elongate member, said carrier member being pivotable aboutsaid first axis from a first position, in which said deFlector is fullyreleased into a second position, in which said deflector is fullydisplaced by the maximum possible distance towards said elongate memberfor deflecting said elongate member, said first and second axes beingaligned with the reaction force exerted by said elongate member on saidthird displacement member when the latter is in said second position,means for effecting said pivotation of said carrier member, and meansfor measuring distortion of said resilient support on movement of saiddisplaceable deflector into said second position, said apparatus beingopen at one side thereof to allow engagement of said engagement memberswith said elongate member by relative laterial movement of saidapparatus and said elongate member.
 2. An apparatus as set forth inclaim 1, wherein said means for effecting pivotation comprise a handlefixed to said carrier.
 3. An apparatus as set forth in claim 1, furthercomprising an arm secured by one end thereof to the support andextending along and spaced from the support, said distortion measuringmeans comprising a mechanical gauge acting between said support and thefree end of said arm.
 4. An apparatus as set forth in claim 1, whereinsaid first, second and third engagement members each comprise a freelyrotatable roller, means being provided for releasably securing saidrollers to said support, whereby said rollers are readily replaceable byrollers of different dimensions.
 5. An apparatus as set forth in claim1, wherein said pivotation means comprises an electric motor.
 6. Anapparatus as claimed in claim 1, wherein said pivotation means comprisesa piston and cylinder and a crank.
 7. An apparatus as claimed in claim1, wherein said pivotation means comprises a handwheel, and a worm andworm connecting said handwheel to said carrier.
 8. An apparatus formeasuring the loading of an elongate member, comprising a resilientelongate support, three engagement members spaced apart along saidresilient support for engaging said elongate member, a carrier mountedon said support, one of said engagement members comprising adisplaceable deflector member mounted on said carrier, a surface on saidcarrier engaging said deflector member, means mounting said carrier formovement relative to said deflector in a direction inclined to saidsurface, and means for effecting the movement of said carrier in saiddirection to move said deflector member from a released position and toan engaged position for deflecting said resilient support, and means formeasuring the deflection of said resilient support as an indication ofthe loading of said elongate member.
 9. An apparatus as set forth inclaim 8, wherein said means for effecting movement of said carriercomprise a manually rotable member in threaded engagement with saidcarrier.
 10. An apparatus as claimed in claim 8, wherein the three ropeengagement members each comprise a freely rotatable roller.
 11. Anapparatus as claimed in claim 10, wherein the rollers are replaceable byrollers of different dimensions for adapting the apparatus to differentrope thicknesses.
 12. An apparatus as claimed in claim 11, wherein thedistortion measuring means comprise a mechanical gauge.
 13. An apparatusas claimed in claim 12, wherein the mechanical gauge is mounted on anarm extending from the support member.
 14. An apparatus as claimed inclaim 13, wherein the arm is movably connected to the support member.15. An apparatus as claimed in claim 8, wherein the measuring meanscomprise an electrical strain gauge connected to the resilient support.16. An apparatus for measuring the loading of an elongate member,comprising a resilient elongate support, first and second engagementmembers spaced apart along said resilient support for engaging one sideof said elongate member, a carrier member pivotable relative to saidresilient support about a first axis substantially midway between saidfirst and second engagement members along said resilient support, athIrd engagement member mounted on said carrier member and pivotablerelative to said support about a second axis for engaging the oppositeside of said elongate member, said carrier member being pivotable aboutsaid first axis from a first position, in which said deflector is fullyreleased into a second position, in which said deflector is fullydisplaced by the maximum possible distance towards said elongate memberfor deflecting said elongate member, means for effecting said pivotationof said carrier member, and means for measuring distortion of saidresilient support on movement of said displaceable deflector into saidsecond position, said apparatus being open at one side thereof to allowengagement of said engagement members with said elongate members byrelative lateral movement of said apparatus and said elongate member.